Novel coupled analysis methods of automotive alternators considering synchronous rectification circuit

Purpose The purpose of this paper is to develop a novel coupled analysis method for synchronous rectification alternators. Design/methodology/approach An ideal diode module is embedded in a rectification circuit. The resistance of the diode module is set such that it is equal to the on-resistance of the MOS-FET modules in the generation mode. In a mode without power generation, the motor voltage is less than the bus voltage; a sufficiently large value is defined for simulating the infinite resistance. Findings Because there is no need to decide the switch timing in advance, only one round of coupled analysis is needed to evaluate the synchronous rectification alternators. Research limitations/implications As limited case study is denoted in this paper, much more case studies are needed to be discussed. Practical implications By using the proposed method, it can be fulfilled that generation characteristic of automotive alternators can be evaluated without using the control simulation or pre-conducted analysis to decide the switch timing. Social implications By using the proposed method, it can be fulfilled that generation characteristic of automotive alternators can be evaluated without using the control simulation or pre-conducted analysis to decide the switch timing. Originality/value In the proposed methods, the definition of diode module differs from that of a conventional coupled analysis.

CALCULATION OF HEAT GENERATION ACCORDING TO SPECIFIED LAW OF FUEL FEEDING AND SIMULATOR VERIFICATION BASED ON DIESEL ENGINE

The results of a heat generation characteristic calculation according to a specified law of fuel feeding on the program developed in Microsoft Excel environ-ment are shown. There is obtained an experimental confirmation of the model of the interconnection be-tween fuel feeding and heat generation in the cylinder of D243E diesel engine.

Effect of Components Thickness on Heat and Mass Transfer Phenomena in Single Cell of PEFC Operated at High Temperature

Since the heat transfer characteristics in Polymer Electrolyte Fuel Cell (PEFC) influences its power generation performance, this study clarifies the temperature characteristics to in-plane direction in single PEFC. In addition, since we expect the heat and mass transfer as well as power generation characteristic are enhanced by decreasing PEM and GDL’s thicknesses, it is effective to investigate the impact of components thickness on them under high temperature operation. This study aims to clarify how to influence PEM and GDL’s thicknesses on not only heat and mass transfer characteristics but also power generation characteristic under high temperature, e.g., 90 °. The present study measured temperature distributions to in-plane direction on cathode separator back of cell by thermograph with power generation changing initial operation temperature as well as relative humidity of inflow gases. As a result, the increase in generated power and the even temperature distribution were obtained due to the decrease in GDL’s thickness. Since the moisture transfer was promoted with decreasing the thickness of PEM, the power generation performance was improved. It was clarified that the impact of GDL’s thickness was larger than that of PEM’s thickness.

Pilot study about the micro hydropower generation by use of flow induced vibration phenomenon

In order to construct a micro power generation system using a piezo-electric element, power generation was tried using excitation oscillation of the bluff cylinder by the vortex shedding from the bluff cylinder. The bluff cylinder consists of a board spring section in which the piezo-electric element was attached, and a body section. The bluff cylinder was inserted into the water flow, the shape and the submersion depth of the bluff cylinder, and the flow velocity were varied, and the power generation characteristic was investigated. As a result, it was found that it can generate electricity by vortex excitation. It was found that the length and the submersion depth of the body section influence power generation. It was shown that the power generation characteristic changes with cross-sectional shape of the bluff cylinder. The most suitable state was the case where the submersion depth was set to 140 mm with a circular cylinder with a span length of 250 mm. It is important to choose the power generation object which suited the use purpose.